title: Cortical superficial siderosis and intracerebral hemorrhage risk in cerebral amyloid angiopathy.
abstract: OBJECTIVE
  To investigate whether cortical superficial siderosis (cSS) on MRI, especially if disseminated (involving more than 3 sulci), increases the risk of future symptomatic lobar intracerebral hemorrhage (ICH) in cerebral amyloid angiopathy (CAA).
  
  
  METHODS
  European multicenter cohort study of 118 patients with CAA (104 with baseline symptomatic lobar ICH) diagnosed according to the Boston criteria. We obtained baseline clinical, MRI, and follow-up data on symptomatic lobar ICH. Using Kaplan-Meier and Cox regression analyses, we investigated cSS and ICH risk, adjusting for known confounders.
  
  
  RESULTS
  During a median follow-up time of 24 months (interquartile range 9-44 months), 23 of 118 patients (19.5%, 95% confidence interval [CI]: 12.8%-27.8%) experienced symptomatic lobar ICH. Any cSS and disseminated cSS were predictors of time until first or recurrent ICH (log-rank test: p = 0.0045 and p = 0.0009, respectively). ICH risk at 4 years was 25% (95% CI: 7.6%-28.3%) for patients without siderosis; 28.9% (95% CI: 7.7%-76.7%) for patients with focal siderosis; and 74% (95% CI: 44.1%-95.7%) for patients with disseminated cSS (log-rank test: p = 0.0031). In Cox regression models, any cSS and disseminated cSS were both independently associated with increased lobar ICH risk, after adjusting for ≥ 2 microbleeds and age (hazard ratio: 2.53; 95% CI: 1.05-6.15; p = 0.040 and hazard ratio: 3.16; 95% CI: 1.35-7.43; p = 0.008, respectively). These results remained consistent in sensitivity analyses including only patients with symptomatic lobar ICH at baseline.
  
  
  CONCLUSIONS
  Our findings indicate that cSS, particularly if disseminated, is associated with an increased risk of symptomatic lobar ICH in CAA. cSS may help stratify future bleeding risk in CAA, with implications for prognosis and treatment.
authors.affiliation: From the Stroke Research Group, Department of Brain Repair and Rehabilitation (A.C., D.J.W.), and Lysholm Department of Neuroradiology (R.J.), UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, UK; Department of Neurology (A.P.P.), Cliniques Universitaires UCL Saint Luc, Brussels, Belgium; Department of Brain Repair and Rehabilitation (R.J.), and Biomedical Research Centre, UCL and the Education Unit (Z.F.), UCL Institute of Neurology, Queen Square, London, UK; Department of Neurology, CHU Mont-Godinne (Y.V., P.L.), and Institute of Neuroscience (Y.V., P.L.), Université Catholique de Louvain, Brussels, Belgium; Department of Clinical Neurosciences (J.-C.B.), University of Cambridge, Addenbrooke's Hospital, Cambridge, UK; and UMR 894 INSERM-Université Paris 5, Sorbonne Paris Cité, Paris, France.
authors.forename: Andreas
authors.initials: A
authors.lastname: Charidimou
authors.forename: Andre Philippe
authors.initials: AP
authors.lastname: Peeters
authors.forename: Rolf
authors.initials: R
authors.lastname: Jäger
authors.forename: Zoe
authors.initials: Z
authors.lastname: Fox
authors.forename: Yves
authors.initials: Y
authors.lastname: Vandermeeren
authors.forename: Patrice
authors.initials: P
authors.lastname: Laloux
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Baron
authors.forename: David John
authors.initials: DJ
authors.lastname: Werring
mesh_terms: D000368:Aged; D016657:Cerebral Amyloid Angiopathy / Q000150:complications* / Q000175:diagnosis; D002540:Cerebral Cortex / Q000473:pathology*; D002543:Cerebral Hemorrhage / Q000150:complications* / Q000175:diagnosis; D015331:Cohort Studies; D016001:Confidence Intervals; D005060:Europe; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D008297:Male; D016016:Proportional Hazards Models; D012806:Siderosis / Q000150:complications*; D014057:Tomography, X-Ray Computed